I have downloaded the JAVA SDK and tried to pritn to a ZEBRA ZD620 using direct USB communication without driver
Printing labels is immediate while getting the printer status take about 10 seconds.
As you can see in the code I have used two ways to get the Host Status:

Connection.sendAndWaitForResponse("~Hs".getBytes(), 2000, 2000, "V");
and
ZebraPrinter.getCurrentStatus();

Any suggestion?

public static void usbDriverlessTest() throws ConnectionException {
System.out.println("Discovered USB printer list:\r\n");

DiscoveredUsbPrinter discoveredPrinter = null;
for (DiscoveredUsbPrinter printer : UsbDiscoverer.getZebraUsbPrinters(new ZebraPrinterFilter())) {
System.out.println(printer);
discoveredPrinter = printer;
}
System.out.println("End USB printer list\r\n");

Connection imz = ConnectionBuilder.build(discoveredPrinter.address);
try {
imz.open();
byte[] hi_return = null;
ZebraPrinter printer = ZebraPrinterFactory.getInstance(imz);

String label = "^XA^FO17,16^GB379,371,8^FS^FT65,255^A0N,135,134^FDTEST^FS^PQ1,0,1,N^XZ";

// printer.sendCommand(label);

SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");

System.out.println(sdf.format(new Date()));
// https://live-zebratechnologies.devportal.apigee.io/thread/35973

PrinterStatus printerStatus = printer.getCurrentStatus();
System.out.println("printerStatus.labelLengthInDots=" + printerStatus.labelLengthInDots);
System.out.println("printerStatus.labelsRemainingInBatch=" + printerStatus.labelsRemainingInBatch);
System.out.println("printerStatus.numberOfFormatsInReceiveBuffer=" + printerStatus.numberOfFormatsInReceiveBuffer);
System.out.println("printerStatus.isReadyToPrint=" + printerStatus.isReadyToPrint);
System.out.println("printerStatus.isReceiveBufferFull=" + printerStatus.isReceiveBufferFull);

System.out.println(sdf.format(new Date()));

hi_return = imz.sendAndWaitForResponse("~Hs".getBytes(), 2000, 2000, "V");

System.out.println(new String(hi_return));

System.out.println(sdf.format(new Date()));

hi_return = imz.sendAndWaitForResponse("~HQES".getBytes(), 2000, 2000, "V");

System.out.println(new String(hi_return));

System.out.println(sdf.format(new Date()));

} catch (ZebraPrinterLanguageUnknownException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
imz.close();
}
}